Photosensitive Drum Toner Supply for Cleaning Blade Shudder
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Solution Overview
Problem
The issue of improper cleaning due to shuddering of the cleaning blade in electrophotographic image forming apparatuses, particularly when the amount of toner supplied to the photosensitive member is low, leading to slip-through of toner and ineffective removal by the cleaning blade.
Innovation Solution
Implementing a controller to manage a potential difference (Vback) between the image bearing member and the developing member, adjusting the Vback during non-image forming operations to reduce friction and supply toner to the cleaning portion, thereby minimizing frictional forces and preventing shuddering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the cleaning blade contacts the photosensitive member to remove toner, then cleaning function is improved, but shuddering occurs when toner amount is low causing improper cleaning
Solution Approach 1:
The patent applies preliminary action by performing a supplying operation before the actual image formation. During this preliminary operation, toner is supplied to the contact portion between the photosensitive member and cleaning blade to lubricate the interface and prevent shuddering during subsequent cleaning operations. This advance preparation ensures stable cleaning contact without vibration-induced improper cleaning.
2Stability of the object's composition
If toner is supplied to the contact portion to reduce friction, then cleaning stability is improved, but toner slip-through occurs during supplying operation
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the Vback (potential difference between photosensitive member and developing member) during the supplying operation. By controlling Vback to be smaller than during normal image formation, the patent modifies the electrostatic forces to prevent toner slip-through while still enabling sufficient toner supply to the cleaning blade contact portion for friction reduction.
3Reliability
If Vback is reduced during supplying operation, then toner slip-through is suppressed, but frictional force reduction may be insufficient
Solution Approach 1:
The patent applies continuity of useful action by maintaining the supplying operation throughout the non-image forming periods (pre-rotation and post-rotation sequences). This continuous supply of toner to the cleaning blade contact portion ensures persistent friction reduction and shuddering prevention, rather than providing only temporary or intermittent lubrication.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Effectively suppresses improper cleaning by reducing frictional forces between the image bearing member and the cleaning blade, ensuring efficient toner removal even during low-toner conditions.
Implementation Method 1
a frictional force between the photosensitive member and the cleaning blade increases
Implementation Method 2
a surface of a photosensitive member as an image bearing member is electrically charged uniformly by a charging member
Implementation Method 3
is exposed to light by an exposure device, so that an electrostatic latent image is formed on the photosensitive member
Implementation Method 4
This electrostatic latent image is developed by being supplied with toner as a developer by a developing device
Data Source
AI summary
An image forming apparatus includes an image bearing member, a charging member, a charging voltage applying portion, an exposure unit, a developing member, a developing voltage applying portion, a cleaning member, and a controller. During a non-image forming operation from a start of rotation of the image bearing member to a start of an image forming operation or from an end of the image forming operation to a stop of the rotation of the image bearing member, in a contact rotation state of the developing member with the image bearing member, the controller effects control so as to execute a supplying operation in which Vback lower or higher than Vback during an image forming operation is generated in a time corresponding to one full rotation of the developing member and toner moved from the developing member to the surface of the image bearing member is supplied to the cleaning portion.